Sphincterotome with improved orientation

ABSTRACT

A sphincterotome including a cutting wire may be configured such that, when activated, the cutting wire assumes a desired cutting position at or near the “12 o&#39;clock” position or any other desired angular configuration. A sphincterotome may have controlled bending characteristics. A distally located micromachined hypotube may, in some instances, provide desired bending characteristics to a sphincterotome.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/245,884, filed Oct. 6, 2008, which claims the benefit of U.S.Provisional Application No. 60/978,336, filed Oct. 8, 2007, the entiredisclosures of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention pertains generally to medical devices and moreparticularly to medical devices such as sphincterotomes.

BACKGROUND

In procedures such as endoscopic sphincterotomy, a sphincterotome may beused in conjunction with an endoscope to provide surgical cutting insideof a patient. Exemplary sphincterotomes are disclosed in commonlyassigned U.S. Pat. Nos. 5,547,469 and 5,868,698 to Rowland et al., thedisclosures of which are incorporated herein by reference. Thesphincterotome may, for example, be used to partially cut open thesphincter muscle for treatment such as removal of common bile ductstones forming an obstruction. A sphincterotome may include a cuttingwire that can be activated by bending the sphincterotome, therebypermitting the cutting wire to extend from the sphincterotome.

However, when activating the cutting wire, it may be difficult tocontrol the exact positioning of the cutting wire. In some instances, itmay be desirable to position the activated cutting wire in an angularconfiguration commonly referred to in the art as the “12 o'clock”position, or in any other desirable angular configuration.

There remains a need, therefore, for an improved sphincterotome that isconfigured such that, when activated, the cutting wire assumes a desiredcutting position at or near the “12 o'clock” position, or any otherdesired angular configuration. A need remains for an improvedsphincterotome with controlled bending characteristics.

SUMMARY

The invention pertains to an improved sphincterotome that is configuredsuch that, when activated, the cutting wire assumes a desired cuttingposition at or near the “12 o'clock” position or any other desiredangular configuration. In some cases, activating the cutting wire mayinclude application of an electrical current, but this is not required.The invention pertains to an improved sphincterotome having controlledbending characteristics.

Accordingly, an illustrative but non-limiting example of the inventionmay be found in a sphincterotome having an elongate shaft and a cuttingelement lumen extending through the elongate shaft. A micromachinedhypotube may be disposed within a distal region of the elongate shaft. Acutting element may be disposed within the cutting element lumen suchthat an exposed portion of the cutting element is disposed exterior tothe micromachined hypotube.

Another illustrative but non-limiting example of the invention may befound in a sphincterotome that is movable between a cutting position anda non-cutting position. The sphincterotome includes an elongate shaftthat defines a cutting wire lumen extending within the elongate shaft. Acutting wire may be disposed within the cutting wire lumen. Thesphincterotome includes apparatus or structure disposed exterior to theelongate shaft that is configured to limit a bending plane of theelongate shaft.

Another illustrative but non-limiting example of the invention may befound in a sphincterotome that has an elongate shaft that defines acutting wire lumen. A cutting wire may be disposed within the cuttingwire lumen. A distal region of the elongate shaft may be configured tohave a greater flexibility in an activating bending plane and a lesserflexibility in an orthogonal bending plane.

The above summary of the present invention is not intended to describeeach disclosed embodiment or every implementation of the presentinvention. The Figures, Detailed Description and Examples which followmore particularly exemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a view of a sphincterotome in accordance with an illustrativebut non-limiting example of the invention;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a view of a micromachined hypotube that may be incorporatedinto the sphincterotome of FIG. 1, in accordance with an illustrativebut non-limiting example of the invention;

FIG. 5 is a top view of a distal portion of the sphincterotome of FIG.1, incorporating the micromachined hypotube of FIG. 4 in accordance withan illustrative but non-limiting example of the invention; and

FIG. 6 is a side view of a distal portion of the sphincterotome of FIG.1, incorporating the micromachined hypotube of FIG. 4 in accordance withan illustrative but non-limiting example of the invention, shown in acurved configuration.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the terms “about” may include numbers thatare rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following description should be read with reference to the drawingswherein like reference numerals indicate like elements throughout theseveral views. The drawings, which are not necessarily to scale, depictillustrative embodiments of the claimed invention.

The present invention generally pertains to a sphincterotome 10, asillustrated in FIG. 1. The sphincterotome 10 can be seen as including aproximal section 12 and a distal section 14. A handle 16 is disposedwithin the proximal section 12 and an elongate shaft 18 extends distallytherefrom. The handle 16 may be formed of any suitable metallic orpolymeric material, such as those discussed hereinafter. The elongateshaft 18 itself has a distal region 20 defining a distal end 22 and aproximal region 24 defining a proximal end 26. In some instances, it iscontemplated that part of the elongate shaft 18 may undergo processingthat may impart a curve or bias thereto, although this is not required.The elongate shaft 18 may be formed of or include any suitable polymericmaterial. In some cases, the elongate shaft 18 may include portions madefrom or including polytetrafluoroethylene, better known as TEFLON®.

A hub 26 may be disposed within the proximal region 24 of the elongateshaft 18. In some instances, if desired, the hub 26 may include a firsthub portion 28 having a side port 30 that may be used to gain fluidaccess to an interior of the elongate shaft 18. The hub 26 may alsoinclude a second hub portion 32 that may, if desired, provide guidewireaccess to the interior of the elongate shaft 18 via a guidewire port 34that is provided within the second hub portion 32. The elongate shaft 18can be seen as extending distally to a distal end 22 of the elongateshaft 18. The elongate shaft 18 may be considered as including the hub26, first hub portion 28 and second hub portion 32. The hub 26 anddefined portions thereof may be formed of any suitable polymericmaterial.

As noted, the elongate shaft 18 includes an interior. FIGS. 2 and 3,which are cross-sections taken through the elongate shaft 18, provideillustrative but non-limiting examples of an interior of the elongateshaft 18. In FIG. 2, which is taken through a relatively proximalportion of the elongate shaft 18, it can be seen that the elongate shaftincludes a first lumen 36 and a second lumen 38. In some instances, theelongate shaft 18 may include only one lumen, or may include three ormore lumens.

In the illustrated embodiment, the first lumen 36 may, for example, be aguidewire lumen in communication with the guidewire port 34 disposedwithin hub 32. The second lumen 38 may, if desired, accommodate acutting element 40. The cutting element 40 may extend from the handle 16to a position within the distal region 20 of the elongate shaft 18. Insome instances, the cutting element 40 may be a cutting wire, as knownin the art. In some cases, the cutting element 40 may be a stranded orbraided wire.

FIG. 3 is a cross-section taken through a relatively distal portion ofthe elongate shaft 18. In this view, only a single lumen 42 is present.In some cases, the first lumen 36 and the second lumen 38 may merge intoa single lumen 42. In some cases, the second lumen 38 (through which thecutting element 40 is disposed) may terminate at a position proximal ofwhere this cross-section is taken as the cutting element 40 itself mayextend external to the shaft or terminate proximal of the cross-sectionpoint. In other cases, the elongate shaft 18 may include one, two, threeor more lumens that extend all the way to the distal end 22 of theelongate shaft 18. In some cases, the elongate shaft 18 may beconfigured to provide rapid exchange capability and thus may include ashort guidewire lumen (not illustrated) extending through a distalportion of the elongate shaft 18.

Returning to FIG. 1, it should be noted that the cutting element 40(seen in FIG. 2) has a distal end (discussed later with respect to FIGS.5 and 6) and a proximal end 44. In some cases, the proximal end 44 maybe secured to the handle 16. More particularly, the handle 16 mayinclude a stationary portion 46 and a movable portion 48. The stationaryportion 46 may be secured to the elongate shaft 18 while the proximalend 44 of the cutting element 40 may be secured to the movable portion48. The movable portion 48 may be slidingly disposed on the stationaryportion 46.

The stationary portion 46 may, if desired, include a thumb ring 50 whilethe movable portion 48 includes one or more finger rings 52. Thus, aphysician or other professional may activate the sphincterotome 10 byholding the thumb ring 50 in his or her thumb and using their fingers topull the finger rings 52 (and thus the movable portion 48) proximally.

The handle 16 may also, if desired, include a connector block 80 thatmay be used to provide communication between the cutting element 40 anda RF heating source, as is known in the art, in order to energize thecutting element 40.

The distal region 20 of the elongate shaft 18 may, as illustrated,include one or more marker bands 54. The marker bands 54, if present,may be formed of any suitable radiopaque material and may have anyappropriate dimensions and/or axial spacing, as desired. In some cases,the marker bands 54 may be visually evident during use, and therefore insome instances, the marker bands 54 may not be formed of a radiopaquematerial but may instead simply be applied using a material of adifferent color. The marker bands 54 may aid in positioning thesphincterotome 10 during a procedure.

The distal region 20 of the elongate shaft 18 also includes elements notexpressly illustrated in FIG. 1. In particular, FIG. 4 provides a viewof a micromachined hypotube 56 that may be disposed within or about atleast a portion of the distal region 20 of the elongate shaft 18. Themicromachined hypotube 56 has a proximal portion 58 defining a proximalend 60 and a distal region 62 defining a distal end 64. Themicromachined hypotube 56 has a first side 66 and a second side 68. Thefirst side 66 may include a first plurality of slots 70 while the secondside 68 includes a second plurality of slots 72. At least some of thefirst plurality of slots 70 may be parallel. At least some of the secondplurality of slots 72 may be parallel.

Each of the first plurality of slots 70 and each of the second pluralityof slots 72 extend only partially around the circumference of themicromachined hypotube 56. In some instances, as illustrated, each ofthe first plurality of slots 70 and each of the second plurality ofslots 72 are at least substantially equally sized in length and width,and start and stop along common lines. While not illustrated, it iscontemplated that the relative axial spacing and/or width of some of theslots within the first plurality of slots 70 and/or the second pluralityof slots 72 may vary in order to provide customized flexibility control.

It can be seen that the micromachined hypotube 56 will have a greaterflexibility in a first bending plane in which, for example, at leastsome of the first plurality of slots 70 open while at least some of thesecond plurality of slots 72 close. Conversely, the micromachinedhypotube 56 will have a reduced flexibility in a second bending planethat is orthogonal to the first bending plane. It can be seen that thefirst bending plane may be referred to as an activating bending planewhile the second bending plane might be referred to as an orthogonalbending plane.

Each slot within the first plurality of slots 68 and the secondplurality of slots may be formed to be at least largely rectangular inshape. In some instances, at least some of the slots may not extend allthe way through micromachined hypotube 56. Each slot may be formed usingany suitable technique, such as saw cutting, a laser, or even byelectrical discharge machining (EDM). Additional suitable techniquesinclude chemical etching and abrasive grinding.

The micromachined hypotube 56 may be formed of any suitable polymeric ormetallic material. In some cases, the micromachined hypotube 56 may beformed of a suitably stiff polymer such as carbon fibers, liquid crystalpolymers, polyimide, and the like. In some instances, the micromachinedhypotube 56 may be formed of a metallic material such as stainless steelor a nickel-titanium alloy such as Nitinol or other metallic orpolymeric shape-memory material. The micromachined hypotube 56 mayinclude a combination of metal tubes and polymer tubes, if desired. Insome cases, the micromachined hypotube 56 may be formed as an integralpart of the elongate shaft 18, or in some instances, the slots mayinstead be formed within the elongate shaft 18 itself.

The micromachined hypotube 56 may be formed having any desired length,width, material thickness, and slot size as required to satisfy therequirements of any particular application. Additional detailsconcerning micromachined hypotube 56, including the manufacture thereof,can be found, for example, in U.S. Pat. No. 6,766,720 and U.S. PatentPublication No. 2004/0181174A2, each of which are incorporated byreference herein to the extent that they do not conflict with thepresent disclosure.

FIGS. 5 and 6 clarify operation of the sphincterotome 10. In FIG. 5, themicromachined hypotube 56 has been disposed about or within the distalregion 20 of the elongate shaft 18. In some cases, the micromachinedhypotube 56 may be disposed about an exterior of the elongate shaft 18.If desired, and to electrically isolate the micromachined hypotube 56from the cutting element 40, a polymeric coating or sheath may beapplied to the micromachined hypotube 56. In some instances, themicromachined hypotube 56 may be molded within the polymeric or othermaterial forming the elongate shaft 18, as desired.

The cutting element 40 includes an exposed cutting portion 74 thatextends from a distal end 76 of the cutting element 40 to a port 78disposed within the elongate shaft 18. As illustrated, the distal end 76of the cutting element 40 is secured directly to the distal region 62 ofthe micromachined hypotube 56. In some cases, it is contemplated thatthe cutting element 40 could instead pass through an aperture (notillustrated) or rest within a slot or channel within the micromachinedhypotube 56 such that the distal end 76 of the cutting element 40 couldinstead be anchored directly to the elongate shaft 18.

As noted previously, the cutting element 40 extends proximally to thehandle 16. The port 78 is an aperture formed within the wall of theelongate shaft 18 and may, if desired, include reinforcing structure(not illustrated). In FIG. 5, the exposed cutting portion 74 can be seento be in a non-cutting position in which the exposed cutting portion 74of the cutting element 40 is at least substantially parallel with theelongate shaft 18.

In FIG. 6, however, the exposed cutting portion 74 of the cuttingelement 40 is in a cutting position in which the exposed cutting portion74 of the cutting element 40 has pulled away from the elongate shaft 18as a result of proximal movement of the movable portion 48 relative tothe stationary portion 46. It can be seen that the micromachinedhypotube 56 provides at least part of the distal region 20 with a smoothcurvature that is free of kinks.

As discussed above, the micromachined hypotube 56 is configured to bemore flexible in a first bending plane and less flexible in a second,orthogonal bending plane. The micromachined hypotube 56 may be securedto the elongate shaft 18 oriented in such a way that when a tensileforce is applied to the cutting element 40, the first bending planecorresponds to the “12 o'clock” direction. As a result, thesphincterotome 10 will reliably or predictably bend in a desireddirection.

In some instances, it is contemplated that the cutting element 40 maynot actuate in exactly a desired direction or plane. This may occur, forexample, as a result of manufacturing tolerances, interference from theanatomy, influence from an endoscope, and the like. Nevertheless, thesphincterotome 10 will, as a result of micromachined hypotube 56,reliably and repeatedly bend in a desired plane.

The devices described herein may include a variety of differentmaterials. These materials may include metals, metal alloys, polymers,metal-polymer composite, and the like, or any other suitable material.Some examples of suitable metals and metal alloys include stainlesssteel, such as 304V, 304L, and 316LV stainless steel; mild steel;nickel-titanium alloy such as linear-elastic or super-elastic nitinol,nickel-chromium alloy, nickel-chromium-iron alloy, cobalt alloy,tungsten or tungsten alloys, MP35-N (having a composition of about 35%Ni, 35% Co, 20% Cr, 9.75% Mo, a maximum 1% Fe, a maximum 1% Ti, amaximum 0.25% C, a maximum 0.15% Mn, and a maximum 0.15% Si), hastelloy,monel 400, inconel 825, or the like; other Co—Cr alloys; platinumenriched stainless steel; or other suitable material.

Some examples of suitable polymers may include polytetrafluoroethylene(PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylenepropylene (FEP), polyoxymethylene (POM, for example, DELRIN® availablefrom DuPont), polyether block ester, polyurethane, polypropylene (PP),polyvinylchloride (PVC), polyether-ester (for example, ARNITEL®available from DSM Engineering Plastics), ether or ester basedcopolymers (for example, butylene/poly(alkylene ether) phthalate and/orother polyester elastomers such as HYTREL® available from DuPont),polyamide (for example, DURETHAN® available from Bayer or CRISTAMID®available from Elf Atochem), elastomeric polyamides, blockpolyamide/ethers, polyether block amide (PEBA, for example availableunder the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA),silicones, polyethylene (PE), Marlex high-density polyethylene, Marlexlow-density polyethylene, linear low density polyethylene (for exampleREXELL®), polyester, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), polytrimethylene terephthalate, polyethylenenaphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI),polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), poly paraphenylene terephthalamide (for example, KEVLAR®),polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMSAmerican Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinylalcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC),polycarbonates, ionomers, biocompatible polymers, other suitablematerials, or mixtures, combinations, copolymers thereof, polymer/metalcomposites, and the like.

In addition, the devices described herein may also be doped with orotherwise include a radiopaque material. Radiopaque materials areunderstood to be materials capable of producing a relatively brightimage on a fluoroscopy screen or another imaging technique during amedical procedure. This relatively bright image aids the user offiltering device in determining their location. Some examples ofradiopaque materials can include, but are not limited to, gold,platinum, molybdenum, palladium, tantalum, tungsten or tungsten alloy,plastic material loaded with a radiopaque filler, and the like.

The invention should not be considered limited to the particularexamples described above, but rather should be understood to cover allaspects of the invention as set out in the attached claims. Variousmodifications, equivalent processes, as well as numerous structures towhich the invention can be applicable will be readily apparent to thoseof skill in the art upon review of the instant specification.

I claim:
 1. A sphincterotome, comprising: an elongate shaft defining acutting wire lumen; a cutting wire disposed within the cutting wirelumen; and a bending plane controlling structure disposed exterior tothe elongate shaft, the bending plane controlling structure including atubular member having a plurality of slots formed therein, the tubularmember having a first side and a second side opposite the first side,wherein the plurality of slots are formed in only the first and secondsides, wherein the tubular member resists bending of the shaft indirections orthogonal to the first and second sides; wherein thesphincterotome is movable between a cutting position and a non-cuttingposition.
 2. The sphincterotome of claim 1, wherein the bending planecontrolling structure provides a directed bending plane when thesphincterotome is activated into the cutting position.
 3. Thesphincterotome of claim 1, wherein the bending plane controllingstructure provides a smooth curvature to a distal portion of theelongate shaft when the sphincterotome is activated into the cuttingposition.
 4. A sphincterotome, comprising: an elongate shaft having alumen formed therein and having a distal end; wherein a distal port isformed in the shaft; wherein the distal port is positioned proximal ofthe distal end of the shaft; a cutting wire extending through the lumen;and a tubular member coupled to the shaft, the tubular member having aplurality of slots formed therein, the plurality of slots being formedonly on two opposite sides of the tubular member, wherein the tubularmember resists bending of the shaft in directions orthogonal to the twoopposite sides; wherein the cutting wire extends through the distal portand along a portion of an outer surface of the tubular member.
 5. Thesphincterotome of claim 4, wherein a first group of parallel slotsextend along a first side of the tubular member.
 6. The sphincterotomeof claim 5, wherein the cutting wire extends along the first side of thetubular member.
 7. The sphincterotome of claim 5, wherein the first sideof the tubular member defines a first preferred bending direction forthe shaft.
 8. The sphincterotome of claim 7, wherein a second group ofparallel slots extend along a second side of the tubular member, thesecond side being opposite the first side.
 9. The sphincterotome ofclaim 8, wherein the second side of the tubular member defines a secondpreferred bending direction for the shaft.
 10. The sphincterotome ofclaim 9, wherein the tubular member resists bending of the shaft indirections orthogonal to the first preferred bending direction and thesecond preferred bending direction.